| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 41/60] arm64: vdso: dont free unallocated pages | Date | Mon, 20 Apr 2020 14:39:19 +0200 |
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From: Mark Rutland <mark.rutland@arm.com>
commit 9cc3d0c6915aee5140f8335d41bbc3ff1b79aa4e upstream.
The aarch32_vdso_pages[] array never has entries allocated in the C_VVAR or C_VDSO slots, and as the array is zero initialized these contain NULL.
However in __aarch32_alloc_vdso_pages() when aarch32_alloc_kuser_vdso_page() fails we attempt to free the page whose struct page is at NULL, which is obviously nonsensical.
This patch removes the erroneous page freeing.
Fixes: 7c1deeeb0130 ("arm64: compat: VDSO setup for compat layer") Cc: <stable@vger.kernel.org> # 5.3.x- Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/arm64/kernel/vdso.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-)
--- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -260,18 +260,7 @@ static int __aarch32_alloc_vdso_pages(vo if (ret) return ret; - ret = aarch32_alloc_kuser_vdso_page(); - if (ret) { - unsigned long c_vvar = - (unsigned long)page_to_virt(aarch32_vdso_pages[C_VVAR]); - unsigned long c_vdso = - (unsigned long)page_to_virt(aarch32_vdso_pages[C_VDSO]); - - free_page(c_vvar); - free_page(c_vdso); - } - - return ret; + return aarch32_alloc_kuser_vdso_page(); } #else static int __aarch32_alloc_vdso_pages(void)
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